guitar neck too narrow ?

I have much difficulty forming a standard A chord without buzzing. My three finger A formation seems too cramped on neck, how can I tell if the neck on my Martin D-35 is too narrow or I simply need better technique. I play both flat pick and finger style and I am not a beginner.

John, That A chord can be pesky. I have tried just about every possible way to play that chord and what works for me( and took a few years to master) is I lay my index finger across the strings to form the chord,i.e. pressing the E,A,C# notes on the D,G,B strings accordingly. Hope this helps. D. Rigby

It may be possible to have a luthier install a new string nut with slightly wider string spacing. I'd suggest having the luthier also check to be sure the action is optimized at the nut so you're not fighting the strings. Also, this is one of those situations where you may benefit from a "master class" lesson with a good teacher. Ask him or her to just watch your left hand. They may find some bad habit fingering issues.

I have the same problem on many guitars (I have 7, and they all give me problems with a 3-finger technique even the classical one) and use the one-finger barre solution. Actually I find it has some benefits b/c the other fingers are free to add in notes. My finger doesn't have to bed back all that much to clear the high-e either. Just take practice. If you do it too hard though, your knuckle will get sore, but eventually you'll build up more flexibility.

If you have trouble playing the chord with three fingers, have you considered trying to use only two? I know a lot of people who play the standard A by covering the strings with two fingers, and several folks who manage with only one. Takes a bit of practice, of course, but it's doable.